High-Intensity Warm-Up Increases Anaerobic Energy Contribution during 100-m Sprint

V ˙ Lamax: determining the optimal test duration for maximal lactate formation rate during all-out sprint cycle ergometry

PURPOSE

This study aimed to ascertain the optimal test duration to elicit the highest maximal lactate formation rate ( V ˙ Lamax), whilst exploring the underpinning energetics, and identifying the optimal blood lactate sampling period.

METHODS

Fifteen trained to well-trained males (age 27 ± 6 years; peak power: 1134 ± 174 W) participated in a randomised cross-over design completing three all-out sprint cycling tests of differing test durations (10, 15, and 30 s). Peak and mean power output (W and W.kg-1), oxygen uptake, and blood lactate concentrations were measured. V ˙ Lamax and energetic contributions (phosphagen, glycolytic, and oxidative) were determined using these parameters.

RESULTS

The shortest test duration of 10 s elicited a significantly (p = 0.003; p < 0.001) higher V ˙ Lamax (0.86 ± 0.17 mmol.L-1.s-1; 95% CI 0.802-0.974) compared with both 15 s (0.68 ± 0.18 mmol.L-1.s-1; 95% CI 0.596-0.794) and 30 s (0.45 ± 0.07 mmol.L-1.s-1; 95% CI 0.410-0.487). Differences in V ˙ Lamax were associated with large effect sizes (d = 1.07, d = 3.15). We observed 81% of the PCr and 53% of the glycolytic work completed over the 30 s sprint duration was attained after 10 s. BLamaxpost were achieved at 5 ± 2 min (ttest 10 s), 6 ± 2 min (ttest 15 s), and 7 ± 2 min (ttest 30 s), respectively.

CONCLUSION

Our findings demonstrated a 10 s test duration elicited the highest V ˙ Lamax. Furthermore, the 10 s test duration mitigated the influence of the oxidative metabolism during all-out cycling. The optimal sample time to determine peak blood lactate concentration following 10 s was 5 ± 2 min.

A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate ( ν La.max) and a modified formula of pure ν La.max (P ν La.max) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships. Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La-) were measured. These parameters were used for different calculations of ν La.max and three energy contributions (phosphagen, W PCr; glycolytic, W Gly; and oxidative, W Oxi). The P ν La.max calculation considered delta La-, time until Wpeak (tPCr-peak), and the time contributed by the oxidative system (tOxi). Other ν La.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr -3.5%) and tPCr-peak. Results: The absolute and relative W PCr were higher than W Gly and W Oxi (p < 0.0001, respectively), and the absolute and relative W Gly were significantly higher than W Oxi (p < 0.0001, respectively); ν La.max (tPCr -3.5%) was significantly higher than P ν La.max and ν La.max (tPCr-peak), while ν La.max (tPCr-peak) was lower than P ν La.max (p < 0.0001, respectively). P ν La.max and ν La.max (tPCr-peak) were highly correlated (r = 0.99; R 2 = 0.98). This correlation was higher than the relationship between P ν La.max and ν La.max (tPCr -3.5%) (r = 0.87; R 2 = 0.77). ν La.max (tPCr-peak), P ν La.max, and ν La.max (tPCr -3.5%) were found to correlate with absolute Wmean and W Gly. Conclusion: P ν La.max as a modified calculation of ν La.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ν La.max (tPCr-peak) and ν La.max (tPCr -3.5%). Because W Oxi and W PCr can differ remarkably between athletes, implementing their values in P ν La.max can establish more optimized individual profiling for elite track cyclists.

Effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults

PURPOSE

Although Pilates is one of the most widely performed physical activities in Korea, no physiological evidence is available regarding its energy recovery ability. Therefore, the purpose of this study was to investigate the effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults.

METHODS

Ten physically active women participated in this study. Pre- and post-lactate threshold (LT) tests were performed to compare jogging/running speeds (S; km·h-1) and heart rates (HR; beats·min-1) at 1.5, 2.0, 3.0, 4.0 mmol·L-1 lactate concentrations (La-). Subjects performed 1 h of low-intensity mat Pilates twice a week for four weeks. During these sessions, exercise intensity was determined based on the heart rate corresponding to individualized low-inten- sity recovery zone 1, which was estimated using a mathematical model of log-log LT1 (from pre-test; &lt; 2 mmol·L-1). All physiological variables were measured before and after exercise intervention.

RESULTS

Significant differences were found in body mass increase and body mass index increase between the pre- and post-tests (p = 0.016 and p = 0.014, respectively, effect size (ES) = 0.13; ES = -0.11). Levels of La- between 1.0 and 1.4 m·s-1 in the post-LT test tended to decrease, although such decrease was not significantly different. Moderate to high positive correlations between differences (Δ) of S and ΔHR at 1.5, 3.0, and 4.0 mmol·L-1La- were observed.

CONCLUSION

Positive correlations between ΔS and ΔHR at certain La- levels indicate that low-intensity mat Pilates based on heart rate corresponding to individualized recovery zone 1 might be recommended for physically active adults.

Physiological Profiling and Energy System Contributions During Simulated Epée Matches in Elite Fencers

PURPOSE

The aim of this study was to investigate physiological responses and energetic contributions during simulated epée matches in elite fencers.

METHODS

Ten elite male fencers participated in simulated epée (direct elimination) matches. Simulated epée matches included 3 bouts of 3 minutes each with 1-minute rests between bouts. During these sessions, physiological variables such as mean and peak heart rate, peak and mean oxygen uptake (VO2peak and VO2mean), metabolic equivalents of task in VO2peak and VO2mean, and blood lactate concentrations (peak lactate concentration and delta blood lactate concentration) were measured. Furthermore, energetic contributions (oxidative [WOxi], glycolytic, and phosphagen) and time-motion variables were estimated.

RESULTS

Values of peak heart rate, mean heart rate, and WOxi (in percentages) were significantly higher in the second and third bouts compared with the first. VO2peak and metabolic equivalents of task in VO2peak were significantly higher in the first bout compared with the third bout. Values of delta blood lactate concentration and glycolytic contribution (in kilojoules and percentages) were significantly lower in the second and third bouts compared with the first. VO2mean and metabolic equivalents of task in VO2mean were significantly higher in the second bout compared with the third bout. Furthermore, WOxi (in kilojoules and percentage) was significantly higher in all bouts compared with phosphagen and glycolytic contributions. Low positive and negative correlations were seen between WOxi, VO2mean, sum of attacks and defense times, and the sum of time without attacks and defenses.

CONCLUSIONS

Direct-elimination epée matches consist of high-intensity intermittent exercise, and the oxidative contribution is 80% to 90%. Improving aerobic conditioning may support high-intensity intermittent actions during entire epée matches in elite fencers.

Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.

Metabolic Energy Contributions During High-Intensity Hatha Yoga and Physiological Comparisons Between Active and Passive (Savasana) Recovery

Purpose: The objective of this study was to investigate metabolic energy contributions during high-intensity hatha yoga (HIHY) and to compare changes in physiological variables between active and passive recovery methods.

Methods: The study involved 20 women yoga instructors (n = 20) who performed 10 min of HIHY (vigorous sun salutation). Upon completion, they were randomly assigned to either active (walking; n = 10) or passive (savasana; n = 10) recovery groups for a period of 10 min. During HIHY, physiological variables such as heart rate (HR_peak and HR_mean), oxygen uptake (VO_2peak and VO_2mean), and blood lactate concentrations (peak La⁻) were measured. Energetic contributions (phosphagen; W_PCR, glycolytic; W_Gly, and oxidative; W_Oxi) in kJ and % were estimated using VO₂ and La⁻ data. Furthermore, the metabolic equivalents (METs) of VO_2peak and VO_2mean were calculated. To compare different recovery modes, HR_post, ΔHR, VO_2post, ΔVO₂, recovery La⁻, and recovery ΔLa⁻ were analyzed.

Results: The results revealed that HR_peak, VO_2peak, and peak La⁻ during HIHY showed no differences between the two groups (p > 0.05). Values of HR_peak, HR_mean, METs of VO_2peak and VO_2mean, and La⁻ during HIHY were 95.6% of HR_max, 88.7% of HR_max, 10.54 ± 1.18, 8.67 ±.98 METs, and 8.31 ± 2.18 mmol·L⁻¹, respectively. Furthermore, W_Oxi was significantly higher compared with W_PCR, W_Gly, and anaerobic contribution (W_PCR + W_Gly), in kJ and % (p < 0.0001). VO_2post and recovery ΔLa⁻ were significantly higher in the active recovery group (p < 0.0001, p = 0.0369, respectively). Values of ΔVO₂ and recovery La⁻ were significantly lower in the active group compared with the passive group (p = 0.0115, p = 0.0291, respectively).

Conclusions: The study concluded that high-intensity hatha yoga which was performed for 10 min is a suitable option for relatively healthy people in the modern workplace who may have hatha yoga experience but do not have time to perform a prolonged exercise. Following active recovery, they can participate in further HIHY sessions during short breaks. Furthermore, a faster return to work can be supported by physiological recovery.